New opportunities for conservation of a rare tiger beetle on developed barrier island beaches

Ellipsoptera lepida, the ghost tiger beetle, is in decline throughout much of its range, especially in the northeastern United States. In New Jersey, the species was known from 18 historic coastal dune and interior upland sites, although modern collection records for the species are rare. Because of the decline of E. lepida, the authors performed extensive surveys of historic sites, as well as potential undocumented sites based on satellite imagery during 2014–2015. One of the previously undocumented sites was an anthropogenic dune on a developed barrier island that had only been constructed 3–4 years prior. Because of its novelty, we conducted more intensive surveys at this site to document abundance and characterize adult and larval habitat. Many historic sites were apparently extirpated or contained small numbers of beetles, although several new populations were located at coastal and inland sites. Abundance of adults and larvae in constructed dunes greatly exceeded densities recorded at other coastal sites. An analysis of vegetation density based on satellite imagery indicates that E. lepida larvae and adults depend on early and mid-successional dunes for optimal habitat. Nearly all inland sites appear to be suitable only because of incidental anthropogenic habitat disturbance while natural disturbance processes play a greater role in maintaining habitat at coastal sites. The high densities we observed in constructed dunes are likely because the constructed dune system is at a single, highly suitable successional stage. This species is unlike another rare coastal tiger beetle native to New Jersey, Habroscelimorpha dorsalis, in that it can persist in the presence of beach vehicle and pedestrian disturbance if suitable dunes are available. Our findings indicate the potential for creating and maintaining additional habitat for Ellipsoptera lepida in parts of its range where it may be declining.